1. Field of the Invention
The present invention relates to a multifunctional optical sensor, in particular for automotive use, comprising a matrix of photodetectors of the CCD or CMOS type having a sensitive area divided into sub-areas, which, individually or combined together, are designated to specific functions of monitoring the scene or measuring environmental parameters.
The scene monitoring functions include monitoring the scene in front, behind or laterally to the vehicle. The frontal monitoring detects, for example, the presence of a vehicle coming from the opposite direction, the presence of a curve or the movement of the vehicle towards the longitudinal demarcation lines of the lane. The monitoring behind the vehicle can, for example, aid parking maneuvers. The lateral monitoring detects, for example, the vehicles that arrive laterally and that are not visible with the external rear-view mirror, since they are in the so-called “blind angle”.
The measurement of environmental parameters comprises, for example, the measurement of fog, rain, window fogging, illumination and solar irradiation conditions.
2. Description of the Related Art
The documents EP-A-1 418 089 and EP-A-1 521 226 by the same Applicant describe multifunctional optical sensors, but refer to multifunctional integration solutions on matrix of photodetectors of the CCD or CMOS type by means of single aperture optics or matrices of lenses positioned in front of the optical window of the sensor. In the document EP-A-1 521 226, each function is associated to a single lens (or to multiple lenses positioned on different matrices) and said lens is associated to a subgroup of photodetectors.
FIG. 1 shows a perspective view of an embodiment of the sensor according to the invention of the document EP-A-1 418 089. Use of single aperture optics limits the possibility of reducing the size of the opto-mechanical system as a whole. Moreover, the complexity of the process for the construction and assembly of the system does not allow significantly to lower the costs of the sensor for large volumes.